The N-550/II SD is an alternative needle (replacement needle) that performs identical to the original needles produced by the manufacturer for use with Toshiba (Aurex) record cartridges. This replacement needle is a "synthetic diamond needle" type. This is a generic model that plays a regular range of sound ranges, with a standard conical shape. General life is about 200 hours. The successor to the TO.37-550/II N-550/II TR.BLU (4951586434702).